Refrigeration evaporator assembly

ABSTRACT

This invention relates to integral sheet metal refrigerator evaporator assemblies of the roll-forged type in final form having one section extending in a complete rectangular loop enclosing the freezing compartment and a depending plate section located in the above-freezing compartment. As an intermediate product a pair of evaporator assemblies are formed of two superposed planar sheets forming a composite panel having two Lshaped patterns of stop-weld material interposed between the sheets arranged in invertedly nested fashion for subsequent lancing from the panel with a minimum of scrap material.

111 3,717,009 1 Feb. 20, 1973 United States Patent Butts [54]REFRIGERATION EVAPORATOR Primary Examiner-Meyer Perlin ASSEMBLYAttorney-William S. Pettigrew, Frederick M. Ritchie and Edward P.Barthel [75] Inventor: Mervin R. Butts, West Milton, Ohio [73] Assignee:General Motors Corporation,

Detroit, Mich.

ABSTRACT This invention relates to integral sheet metal refrigeratorevaporator assemblies of the roll-forged type in final form having onesection extending in a complete rectangular loop enclosing the freezingcompartment [22] Filed: April 26, 1971 and a depending plate sectionlocated in the abovefreezing compartment. As an intermediate product apair of evaporator assemblies are formed of .two superposed planarsheets forrning a composite panel having two L-shaped patterns ofstop-weld material interposed between the sheets arranged in invertedlynested fashion for subsequent lancing from the'panel with aminimum ofscrap material.

i m WW0 N m n m M .m A uh P ""5 C S WW2 m E W r M 5 u 0 mm" m T 4 an" eS 7 n h D 3 a" 1 mmm R m mme 0 t N 1 m U w m P Sun A UIF 1]] .l 1 2100 62 555 5 [Ii 2,795,117 6/1957 Herndon 2,966,781 1/1961Schacfcr.................................62/523 3 Claims, 10 DrawingFigures PAIENTEDF'EBZOIW 3.717; 009 siim 1 or 2 INVENTOR.

BY Mervin f3 buzts W/fiw ATTORNEY PATENTEDFEBZOIQB. 3.717.009

SHEET 20F 2 I'N VENTOR.

BY Merw'nffuzfs wad/M ATTORNEY REFRIGERATION EVAPORATOR ASSEMBLY Thisinvention relates to refrigeration evaporators of the roll-forged typeand more particularly to an intermediate composite panel product formanufacturing a pair of integral evaporator assemblies.

In the prior art it has been proposed to manufacture integral plate-typeevaporators for two-compartment refrigerators having a freezingcompartment for storing frozen foods and an above-freezing compartmentfor the storage of fresh food vertically spaced therefrom. The prior artis exemplified by U. S. Pat. No. 2,795,113 issued June ll, 1957 to C. H.Wirtz, and U. S. Pat. No. 2,986,901 issued June 6, l96l, to E. F.Hubacker. Such prior art evaporators propose a box-shaped section bentto form a plurality of sides defining a freezer compartment and a platesection depending from the first section for refrigerating theabove-freezing food storage compartment of the refrigerator. Theseunitary plate-type evaporators are formed from two superposed plan'arsheets having interconnected refrigerant flow passages formed therein bysuitable patterns of stop-weld or weld preventing material and thuseliminate the need for a plurality of separate connecting tubes andtheir attendant expensive heliarc welded connections.

It is an object of this invention to provide for the economicalmanufacture of integral plate-type evaporators by fabricating twosubstantially identical planar blank evaporator assemblies in nestedinverted fashion whereby the pair of evaporator assemblies may be lancedfrom a single rectangular roll-forged composite panel with a minimum ofscrap material.

Another object of this invention is to provide an improved intermediateproduct for the manufacture of integral evaporator freezer andrefrigerator plate-type heat exchanger assemblies formed from twosuperposed planar sheets having a pair of L-shaped patterns ofweld-preventing or stop-weld material interposed between the sheetswherein the patterns are arranged in reverse conformity such that eachassembly has two spaced evaporator sections joined together by anintegrally formed neck portion whereby they may be lanced from a singlerectangular roll-forged panel with a minimum of scrap material.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred form of the present invention is clearlyshown.

In the drawings:

FIG. 1 is a fragmentary perspective view largely schematic showing theinvention applied to a modern refrigerator;

FIG. 2 is a plan view of a pair of evaporating assemblies shown in FIG.1 in nested condition before the blanking and forming thereof;

FIG. 3 is a plan view of one of the single evaporating assemblies shownin FIG. 1 in the inflated and lanced condition with the expandedrefrigerant passages indicated thereon but before the evaporatorsections have been bent into final shape;

FIG. 4 is a development plan view of an evaporator assembly indicatingthe integral securing means and fold lines thereof before the evaporatorsections have been bent into final shape;

FIG. 5 is a front elevational view showing the relationship of theevaporators after installation into the refrigerator;

FIG. 6 is a view taken on line 66 of FIG. 4;

FIG. 7 is a view taken on line 7-7 of FIG. 4;

FIG. 8 is a view taken on line 8-8 of FIG. 4;

FIG. 9 is a view taken on line 9-9 of FIG. 5 and;

FIG. 10 is a fragmentary sectional view taken substantially on line10-10 of FIG. 3.

Referring now to FIG. 1 of the drawings, wherein a preferred embodimentof the invention has been shown, reference numeral 10 generallydesignates a portion of a conventional refrigerator cabinet having aninsulated frozen food storage compartment 12 in the upper portionthereof, an insulated but relatively higher temperature fresh foodstorage compartment 14 in the mid portion, and an uninsulated machinerycompartment (not shown), arranged in the lower portion. In order tosimplify the disclosure no door has been shown whereas preferably twodoors would be provided for closing the openings to the compartments inaccordance with standard practice. An integral platetype evaporatorassembly is shown in development form at 1 6 in FIG. 4 and includesblank section and plate section 22. A formed rectangular loop portion 18provides a box-shaped evaporator freezer for refrigerating the frozenfood storage compartment 12 and depending evaporator plate section 22 isprovided for refrigerating the above freezing compartment 14 in whichthe unfrozen foods are adapted to be stored.

A refrigerant liquifying system comprising a motorcompressor unit 24 anda condenser 26, diagrammatically illustrated, are mounted in themachinery compartment and serve to supply liquid refrigerant through arestrictor or capillary tube 28 connected to the outlet of thecondenser.

The capillary tube 28 extends within suction line 30 to a combinedentrance and exit 52 (FIG. 3) of the rectangular loop evaporator freezer18. The details of one such combined entrance and exit arrangement isshown in U.S. Pat. No. 2,979,922 the disclosure of which is incorporatedby reference herein.

A thermostatically operated switch 32 which includes a bulb 34 arrangedin contact with thelower edge of the evaporation section 22 is used forstarting and stopping the motor compressor unit 24 in response torefrigeration requirements. The switch 32 is of the type which isadapted to close the circuit to the motor compressor unit when thetemperature of the bulb is a few degrees above the melting temperatureof the frost which may form on the evaporation section 22 during the Oncycle and is adapted to open the circuit when the temperature of thebulb approaches 0 fahrenheit. The relative size of the evaporatorsections and the arrangement of the passages therein are such as toprovide for automatic defrosting of the evaporator section 18.

The pair of identical evaporator assemblies 16 and 16 are fabricatedfrom two superposed planar sheets forming a composite panel indicated at35 in FIG. 2, having a pattern of weld preventing or stop weld materialinterposed between the sheets in a manner shown generally in the WirtzU.S. Pat. No. 2,795,113.

As assemblies 16 and 16 are identical only assembly 16 is shown completein development in FIG. 4. The

blank section is bent in rounded curves to form the rectangular loopportion 18 by means of the transversely extending substantially parallelfold areas A, B, C, D to provide a first side panel 36, a top panel 37,a second side panel 38 and a bottom panel 39 serially arranged in theorder named. The panels 36-39 are bent at right angles to each other toform freezer surfaces for the top and bottom and sides of thebelow-freezing compartment 12 while the depending section 22 extendsinto the above freezing compartment 14. The rectangular loop evaporatorportion 18 is connected to the plate evaporator section 22 by anintegral web or neck portion 42, containing refrigerant passagesconnecting with the plate section 22 and spaced parallel and adjacentthe rear wall of the above-freezing compartment 14. The capillary tube28, connected to the outlet of the condenser 26, extends within thesuction line 30 to the combined entrance and exit 52 of the rectangularloop portion 18. This combined entrance and exit extends through arestricted passage 54 in the loop portion 18 while the suctionline 30fits into and connects with a much larger passage 56 having a sideentrance 58.

Referring now to FIG. 3 which shows a plan view of the lanced evaporatorassembly 16 after the internal passages have been dilated, it will beseen that the restricted portion 54 connects directly with a passage 60extending to an entrance 62 at the lower right-hand corner of the blankevaporator section 20. The blank section 20 is provided with the wafflepattern of refrigerant passages substantially throughout its entire areaand has the entrance 62 on one side and connecting with passage 60 andexit 64 connecting with a passage 66 extending parallel to thelongitudinal edge 67 of blank section 20 through the neck portion 42 tothe plate evaporator section 22. The plate evaporator section 22 may beprovided with a combination of a waffle-type of passage section 68 and aserpentine passage 69 as shown or exclusively with either type ofpassage as desired. The refrigerant flows from the passage 69 throughthe passage 70 in the neck portion 42 -to the passage72 extendingthrough the blank section 20 which there connects the refrigerantpassage 58 connecting with the side of the passage 56. and the suctionline 30 for return to the motor compressor unit 24.

As seen in FIG. 2 a pair of complete evaporators are preferably made inflat form from a pair of rectangular ,with stop-weld material to providea composite homogeneous member.

In the present invention two generally L-shaped patterns of stop-weld,similar to the pattern of FIG. 3, are

applied to the surface of one of the sheets 76 or 78. An inflation passin the form of a band or stripe of stopweld material is applied to onesurface of one of the sheets in the marginal area between the assembliesl6, 16 of the composite panel 35 as indicated by thepass 82. Theinflation pass 82 extends to the upper longitudinal edge 67' ofcomposite panel 35 and this unwelded portion has a needle inserted andthe unwelded stopweld pattern of both integral evaporator assemblies 16and 16' are thereafter inflated by means of fluid pressure entering boththe combined entrance and exits 52 and 52'.

Each evaporator assembly 16, 16 is then lanced out I by trimming toremove the marginal areas such that each assembly 16, 16 appears asshown in FIG. 4. Thus the composite rectangular panel 35 contains twointerconnected whole patterns of separation material each arranged in anL-shape configuration. The L-shaped patterns are oriented in nestedfashion such that the evaporator assemblies have their blank sections20, 20' extending longitudinally in offset manner resulting in, forexample, the plate section 22 of assembly 16 being positioned insubstantially longitudinal alignment with blank 20 and adjacent to thefirst side panel 36' of assembly 20'. As each evaporator assembly isformed with its plate section 22 and its associated neck portion 42having a combined transverse dimension slightly greater than thetransverse dimension of its blank section 20 the assemblies interfit inreverse conformity enabling the assemblies to be lanced from thecompositepanel 35 with a minimum of scrap material. As the amount ofscrap material is a critical factor in equating the cost of an integralevaporator assembly with that of separately formed evaporatorsapplicants achievement of minimizing the amount of waste panel materialhas resulted in a practical low cost integral evaporator assembly.

Further included in the L-shaped evaporator assemblies are a pluralityof recesses 92 and openings 94 cut or stamped around the peripherythereof. Specifically,

recesses 92 and openings 94 are cut in the flanges 9698 located alongthe front edge of the evaporator blank 20. These recesses and slots maybe formed by any suitable method as by a punch press operation and theyprovide means whereby thenew and improved evaporator assembly may beassembled into its complete rectangular loop 18 shown in FIG. 5 bybending along the transverse fold areas A, B, C and D. The flanges 96-99are shown tumed-out as seen in FIG. 7 to provideouter flanges of theformed freezer evaporator loop 18 which may be used for affixing theevaporator directly to a refrigerator liner side wall (not shown) as bymeans of a plurality of rivets extending through the openings 94 on aliner front wall portion and the evaporator loop 18. The front flange.96-99 of the freezer evaporator 18 are preferably positioned rear?wardly from the front edge of the liner so that the evaporator plus thefreezer metallic rear wall, shown at 100 in FIG. 9, cooperate to formthe rear, top, bottom and'side walls of a freezer compartment 12 havingan access opening at the front thereof closed by means of a door (notshown). a

As seen in FIG. 8 the side wall panel 36 includes a step-up to alaterally extending narrow flange section 101 that overlies the flange102 of bottom panel 39 and is secured thereto by any suitable means,such as screws 103 (FIG. 1) extending through apertures 104. Theconnecting entrance passage 52 located in plate 105 connects with thecapillary tube 28 located adjacent the upper right-hand corner of sidepanel 36.

The freezer evaporator rectangular loop 18 is connected to therefrigerator evaporator plate section 22 by integral neck portion 42interconnecting these parts at the rear edge of the bottom panel 39 ofthe freezer evaporator 18 with refrigerant flow developed passageways 65and 70 to eliminate separate connecting tubes. This integral arrangementprovides an evaporator assembly with greater structural strength and, atthe same time, attains a more complete utilization of the roll-forged,lanced and folded technique. As seen in FIG. 4 the portion of free edge67 of bottom panel 39 has an intermediate recessed edge portion definedby notches 106, 108 which are lanced out of bottom panel 39 on eitherside of neck portion 42 such that the neck portion 42 is substantiallycentered on the transverse centerline of the bottom panel. This allowsthe neck portion to be bent into a smooth reverse curve as seen in FIG.9. Thus, the evaporator plate section 22 can be located inwardly fromand parallel to the rear wall 100 of the freezer and spaced forwardlytherefrom such that evaporator plate 22 is positioned adjacent the innerback wall of the refrigerator or above-freezing compartment 14 wherebykinking of the passageways 65 and 70 is eliminated. It will be notedthat while the refrigerant passageways are shown in FIG. as formed inboth sheets 76 and 78 it will be appreciated that the passageways couldbe formed primarily in only one sheet without departing from the scopeof the present invention as shown in US. Pat. No. 2,773,300 issued Jan.15, 1957 to J. S. Palmer. The Palmer patent also disclosed various meansfor securing the sheets such as a copper brazing process which could besubstituted for applicants preferred roll-forged securing means.

In this regard the term inverted is used in the sense i that oneevaporator assembly is positioned on the panel 35 as if it were rotated180 to nest or interfit in reverse conformity with a second assembly.Thus, after the assemblies are lanced from the panel either assembly maybe rotated or turned end-for-end within a common plane to provide twosubstantially identical evaporator assemblies.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is:

1. In combination a composite roll-forged rectangular panel formed oftwo superposed planar sheets having a pattern of stop-weld materialbetween the sheets to form a pair of substantially identical integralevaporator assemblies in planar development form such that each of saidassemblies may be formed for ultimate use in cooling both a freezercompartment and an above-freezing compartment of a refrigerator, eachsaid evaporator assembly having a generally L-shaped configurationdefining a freezer compartment evaporator blank section and anabove-freezing compartment refrigerator evaporator plate section joinedtogether by an integrally formed neck portion, the pattern of stopweldmaterial forming a refrigerant circuit in the sections of each saidevaporator assembly and which are connected together by refrigerantpassages in their associated neck portion, each said evaporator assemblyhaving its freezer evaporator blank section extending longitudinally onsaid composite panel presenting a first side panel, a top panel, asecond side panel and a bottom panel foldably connected by substantiallyparallel transversely extending fold areas and serially arranged in theorder named, each said refrigerator evaporator plate section joined byits neck portion along one longitudinal side edge of its associatedbottom panel,each said evaporator plate section and its associated neckportion having a combined transverse dimension substantially equal tothe transverse dimension of the freezer compartment evaporator blanksection, said evaporator assemblies oriented on said composite panel inoffset inverted fashion such that the refrigerator freezer compartmentevaporator plate section of each evaporator assembly is positioned inlongitudinal alignment with and adjacent to the first side panel of theother evaporator assembly whereby said pair of evaporator assembliesinterfit in reverse conformity enabling said assemblies to be lancedfrom said composite panel with a minimum of scrap material locatedintermediate the adjacent edges upon the lancing of said evaporatorassemblies.

2. In combination a composite roll-forged rectangular panel formed oftwo superposed planar sheets having a pattern of stop-weld materialbetween the sheets to form a pair of first and second substantiallyidentical integral evaporator assemblies in planar development form forultimate use in a refrigerator, each said evaporator assembly having agenerally L-shaped configuration defining a freezer evaporator blanksection and a refrigerator evaporator plate section joined together byan integrally formed neck portion, the pattern of stop-weld materialforming a refrigerant circuit in the sections of each said evaporatorassembly and which are connected together by refrigerant passages intheir associated neck portion, each said evaporator assembly having itsfreezer evaporator blank section extending longitudinally on saidcomposite panel representing a first side panel, a top panel, a secondside panel and a bottom panel foldably connected by substantiallyparallel transversely extending fold areas and serially arranged in theorder named, each said refrigerator evaporator plate section joined byits neck portion along one longitudinal side edge of its associatedbottom panel, each said refrigerator evaporator plate section and itsassociated neck portion having a combined transverse dimension slightlylarger than the transverse dimension of the freezer evaporator blanksection whereby the coextensive opposed portions of the blank sectionsare separated by an intermediate marginal area, each said evaporatorassembly having a combined inlet and outlet passage located at thetransverse edge of each first side panel, said evaporator assembliesoriented on said composite panel in offset inverted fashion such thatthe refrigerator evaporator plate section of said first evaporatorassembly is positioned in longitudinal alignment with and adjacent tothe first side panel of said second evaporator assembly whereby saidfirst and second evaporator assemblies interfit in reverse conformityenabling said assemblies to be lanced from said composite panel with aminimum of scrap material, a single inflated passageway provided by thestop-weld material extending in a transverse direction from onelongitudinal edge of said composite panel and located between the firstside panel of said second evaporator blank section and the evaporatorplate section of said first evaporator assembly, said passageway havinga tap connecting with the combined inlet and outlet of said secondevaporator blank section, said single passageway thence having a 90 turnto extend longitudinally in said intermediate marginal area to aposition beyond the first side panel of said first evaporator assembly,said passageway thence having a U-shaped turn connecting with thecombined inlet and outlet of said first evaporator assembly whereby saidfirst and second evaporator assembly refrigerant circuits are inflatedby said single passageway.

3. In a household refrigerator having a freezer compartment and abovefreezing compartment, means for' the operation of said means forsupplying liquid refrigerant to said sections, the improvement whereinsaid rectangular loop section is formed from a blank section presentinga first side panel, a top panel, a second side panel and a bottom panelserially arranged in the order named and foldably connected by foldareas forming three comer junctures of said rectangular loop, a verticalback wall closing the rear open end of said rectangular loop, saidbottom panel having a rearwardly facing horizontal free edge, said freeedge having an intermediate recessed edge portion centered on thetransverse centerline of said bottom panel, a relatively narrow neckportion extending from said recessed edge integrally connecting saiddepending plate section with said bottom panel, inflated refrigerantpassageways formed in said neck portion interconnecting said evaporatorsections, said neck portion being bent into a smooth reverse curve suchthat said plate section is arranged in parallel with the rear wall ofsaid freezing compartment and spaced forwardly therefrom for location insaid above freezing compartment whereby kinking of said passageways insaid neck portion is eliminated.

1. In combination a composite roll-forged rectangular panel formed oftwo superposed planar sheets having a pattern of stop-weld materialbetween the sheets to form a pair of substantially identical integralevaporator assemblies in planar development form such that each of saidassemblies may be formed for ultimate use in cooling both a freezercompartment and an above-freezing compartment of a refrigerator, eachsaid evaporator assembly having a generally L-shaped configurationdefining a freezer compartment evaporator blank section and anabove-freezing compartment refrigerator evaporator plate section joinedtogether by an integrally formed neck portion, the pattern of stop-weldmaterial forming a refrigerant circuit in the sections of each saidevaporator assembly and which are connected together by refrigerantpassages in their associated neck portion, each said evaporator assemblyhaving its freezer evaporator blank section extending longitudinally onsaid composite panel presenting a first side panel, a top panel, asecond side panel and a bottom panel foldably connected by substantiallyparallel transversely extending fold areas and serially arranged in theorder named, each said refrigerator evaporator plate section joined byits neck portion along one longitudinal side edge of its associatedbottom panel, each said evaporator plate section and its associated neckportion having a combined transverse dimension substantially equal tothe transverse dimension of the freezer compartment evaporator blanksection, said evaporator assemblies oriented on said composite panel inoffset inverted fashion such that the refrigerator freezer compartmentevaporator plate section of each evaporator assembly is positioned inlongitudinal alignment with and adjacent to the first side panel of theother evaporator assembly whereby said pair of evaporator assembliesinterfit in reverse conformity enabling said assemblies to be lancedfrom said composite panel with a minimum of scrap material locatedintermediate the adjacent edges upon the lancing of said evaporatorassemblies.
 1. In combination a composite roll-forged rectangular panelformed of two superposed planar sheets having a pattern of stopweldmaterial between the sheets to form a pair of substantially identicalintegral evaporator assemblies in planar development form such that eachof said assemblies may be formed for ultimate use in cooling both afreezer compartment and an above-freezing compartment of a refrigerator,each said evaporator assembly having a generally L-shaped configurationdefining a freezer compartment evaporator blank section and anabove-freezing compartment refrigerator evaporator plate section joinedtogether by an integrally formed neck portion, the pattern of stop-weldmaterial forming a refrigerant circuit in the sections of each saidevaporator assembly and which are connected together by refrigerantpassages in their associated neck portion, each said evaporator assemblyhaving its freezer evaporator blank section extending longitudinally onsaid composite panel presenting a first side panel, a top panel, asecond side panel and a bottom panel foldably connected by substantiallyparallel transversely extending fold areas and serially arranged in theorder named, each said refrigerator evaporator plate section joined byits neck portion along one longitudinal side edge of its associatedbottom panel, each said evaporator plate section and its associated neckportion having a combined transverse dimension substantially equal tothe transverse dimension of the freezer compartment evaporator blanksection, said evaporator assemblies oriented on said composite panel inoffset inverted fashion such that the refrigerator freezer compartmentevaporator plate section of each evaporator assembly is positioned inlongitudinal alignment with and adjacent to the first side panel of theother evaporator assembly whereby said pair of evaporator assembliesinterfit in reverse conformity enabling said assemblies to be lancedfrom said composite panel with a minimum of scrap material locatedintermediate the adjacent edges upon the lancing of said evaporatorassemblies.
 2. In combination a composite roll-forged rectangular panelformed of two superposed planar sheets having a pattern of stop-weldmaterial between the sheets to form a pair of first and secondsubstantially identical integral evaporator assemblies in planardevelopment form for ultimate use in a refrigerator, each saidevaporator assembly having a generally L-shaped configuration defining afreezer evaporator blank section and a refrigerator evaporator platesection joined together by an integrally formed neck portion, thepattern of stop-weld material forming a refrigerant circuit in thesections of each said evaporator assembly and which are connectedtogether by refrigerant passages in their associated neck portion, eachsaid evaporator assembly having its freezer evaporator blank sectionextending longitudinally on said composite panel representing a firstside panel, a top panel, a second side panel and a bottom panel foldablyconnected by substantially parallel transversely extending fold areasand serially arrangeD in the order named, each said refrigeratorevaporator plate section joined by its neck portion along onelongitudinal side edge of its associated bottom panel, each saidrefrigerator evaporator plate section and its associated neck portionhaving a combined transverse dimension slightly larger than thetransverse dimension of the freezer evaporator blank section whereby thecoextensive opposed portions of the blank sections are separated by anintermediate marginal area, each said evaporator assembly having acombined inlet and outlet passage located at the transverse edge of eachfirst side panel, said evaporator assemblies oriented on said compositepanel in offset inverted fashion such that the refrigerator evaporatorplate section of said first evaporator assembly is positioned inlongitudinal alignment with and adjacent to the first side panel of saidsecond evaporator assembly whereby said first and second evaporatorassemblies interfit in reverse conformity enabling said assemblies to belanced from said composite panel with a minimum of scrap material, asingle inflated passageway provided by the stop-weld material extendingin a transverse direction from one longitudinal edge of said compositepanel and located between the first side panel of said second evaporatorblank section and the evaporator plate section of said first evaporatorassembly, said passageway having a tap connecting with the combinedinlet and outlet of said second evaporator blank section, said singlepassageway thence having a 90* turn to extend longitudinally in saidintermediate marginal area to a position beyond the first side panel ofsaid first evaporator assembly, said passageway thence having a U-shapedturn connecting with the combined inlet and outlet of said firstevaporator assembly whereby said first and second evaporator assemblyrefrigerant circuits are inflated by said single passageway.